Trust me - you can have stubby little fingers and play - I'm proof. I've got a friend with even less likely guitar playing hands and he's very good. Heck, he built two of my guitars!
So far my kids are intensely interested in music but do not play muck of anything. the oldest can play some guitar and the second some keyboard. The other two are only 7. Heck, even the adopted one is very musical.
Speaking of tuners this thing is a really neat, utterly convenient and cheap guitar tuner -
http://www.stewmac.com/shop/Tuners/E...tal_Tuner.html